This invention relates to wire straighteners and, in particular, to wire straighteners comprising a series of rolls carried on a frame so as to engage opposite sides of a wire and flex and straighten the wire passing between the rolls.
Among the variety of wire straighteners available, one of two types is generally used. One is the rotary straightener having adjustable, offset dies which rotate about the wire at high speed, e.g., several thousand revolutions per minute. These machines tend to be both dangerous and extremely noisy and must be operated in a suitable enclosure for the safety of factory personnel. In addition, the quality or accuracy of the straightening depends upon the experience and skill of the person adjusting the dies. Also, the straightener must be motor driven, requiring belts and guards for the driving equipment, further increasing the cost of the straightener.
Roll straighteners do not require rotary motion or driving equipment. The wire is drawn through a series of rolls so that the wire follows a bent path, flexing in one direction and then in the opposite direction, usually undergoing a decreased amount of flexure as it proceeds through the straightener.
Several types of roll straighteners are available with differing methods for adjusting the rolls. With each, however, once a setting has been found for a specific size and type of wire, usually by trial and error, the settings cannot be repeated since there are no accurate reference points.
One approach to the problem, discussed in U.S. Pat. No. 3,343,574, has been to provide individual linear scales for each roll. As this patent recognizes, some means must be provided for exaggerating the readings to obtain reproducible results. The roll straightener described in this patent, as with others in the art, utilizes individually adjustable rolls. Setting each roll, even with improved scales, is tedious. Further, depending upon the number of rolls, the cumulative error with each setting may obviate reproducibility, thereby requiring skilled personnel to adjust the machine for each wire change.